Package org.apache.tinkerpop.gremlin.structure

Interface Edge

All Superinterfaces:

Element

public interface Edge
extends Element

An Edge links two Vertex objects. Along with its Property objects, an Edge has both a Direction and a label. The Direction determines which Vertex is the tail Vertex (out Vertex) and which Vertex is the head Vertex (in Vertex). The Edge label determines the type of relationship that exists between the two vertices.

Diagrammatically:

 outVertex ---label---> inVertex.
 

Author:

Marko A. Rodriguez (http://markorodriguez.com), Stephen Mallette (http://stephen.genoprime.com)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Edge.Exceptions	Common exceptions to use with an edge.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_LABEL	The default label to use for an edge.

Method Summary

Modifier and Type	Method	Description
default Iterator<Vertex>	bothVertices()	Get both the outgoing and incoming vertices of this edge.
default Vertex	inVertex()	Get the incoming/head vertex of this edge.
default Vertex	outVertex()	Get the outgoing/tail vertex of this edge.
<V> Iterator<Property<V>>	properties(String... propertyKeys)	Get an Iterator of properties where the propertyKeys is meant to be a filter on the available keys.
Iterator<Vertex>	vertices(Direction direction)	Retrieve the vertex (or vertices) associated with this edge as defined by the direction.

Methods inherited from interface org.apache.tinkerpop.gremlin.structure.Element

addLabel, dropLabel, dropLabels, graph, id, keys, label, labels, property, property, remove, value, values

Field Details

DEFAULT_LABEL

static final String DEFAULT_LABEL

The default label to use for an edge. This is typically never used as when an edge is created, an edge label is required to be specified.

See Also:

• Constant Field Values

Method Details

vertices

Iterator<Vertex> vertices(Direction direction)

Retrieve the vertex (or vertices) associated with this edge as defined by the direction. If the direction is Direction.BOTH then the iterator order is: Direction.OUT then Direction.IN.

Parameters:

direction - Get the incoming vertex, outgoing vertex, or both vertices

Returns:

An iterator with 1 or 2 vertices

outVertex

default Vertex outVertex()

Get the outgoing/tail vertex of this edge.

Returns:

the outgoing vertex of the edge

inVertex

default Vertex inVertex()

Get the incoming/head vertex of this edge.

Returns:

the incoming vertex of the edge

bothVertices

default Iterator<Vertex> bothVertices()

Get both the outgoing and incoming vertices of this edge. The first vertex in the iterator is the outgoing vertex. The second vertex in the iterator is the incoming vertex.

Returns:

an iterator of the two vertices of this edge

properties

<V> Iterator<Property<V>> properties(String... propertyKeys)

Get an Iterator of properties where the propertyKeys is meant to be a filter on the available keys. If no keys are provide then return all the properties.

Specified by:

properties in interface Element